Staff at the centre will take over much of the work of the London control centre at West Drayton, near Heathrow airport.

But passengers are likely to experience flight delays for a few days following the opening and a reorganisation of airspace in Europe.

Chief executive of NATS, Richard Everitt, said: "Swanwick's entry into service represents a remarkable technical achievement. Britain can now boast the most technically advanced air traffic control centre in the world.

"Today's successful switch of operations from West Drayton to Swanwick, is one of the largest and most complex logistical transitions in air traffic history."

Over the next 10 years NATS hopes to transfer air traffic services for London airports and the military to Swanwick.

Mr Everitt added: "Swanwick gives us the technological advances and operational headroom we need to handle safely a further million flights a year by 2011, in addition to the two million we handle today.

"We also plan to shorten flight delays from 1.5 minutes per flight to a new average of one minute or less. The project is capable of providing world class air traffic control services for the next 30 years."

The repeated delays to the opening of Swanwick have been due to computer software problems at a centre which will contain state-of-the-art systems.

The delays meant that the cost of the centre rose by nearly £150 million on top of the original figure of £475 million.

Over the coming weeks, NATS has advised its airline customers that temporary restrictions on the volume of flights may be imposed as controllers become familiar with the layout of the new centre.

The transfer of operations was planned to take place at a quiet time of the year.

The Swanwick opening follows last year's part-privatisation of NATS, with 46% of the company being taken over by an airline consortium which includes British Airways and Sir Richard Branson's airline Virgin Atlantic.

The downturn in air traffic since September 11 has severely hit NATS which has already announced staff cuts.